As Americans downsize in the aftermath of a colossal real estate bust, at least one tiny corner of the housing market appears to be thriving. To save money or simplify their lives, a small but growing number of Americans are buying or building homes that could fit inside many people’s living rooms, according to entrepreneurs in the small house industry.

Some put these wheeled homes in their backyards to use as offices, studios or extra bedrooms. Others use them as mobile vacation homes they can park in the woods. But the most intrepid of the tiny house owners live in them full-time, paring down their possessions and often living off the grid.

“It’s very un-American in the sense that living small means consuming less,” said Jay Shafer, 46, co-founder of the Small House Society, sitting on the porch of his wooden cabin in California wine country. “Living in a small house like this really entails knowing what you need to be happy and getting rid of everything else.”

Shafer, author of “The Small House Book,” built the 89-square-foot house himself a decade ago and lived in it full-time until his son was born last year. Inside a space the size of an ice cream truck, he has a kitchen with gas stove and sink, bathroom with shower, two-seater porch, bedroom loft and a “great room” where he can work and entertain — as long as he doesn’t invite more than a couple guests.

He and his family now live in relatively sprawling 500-square foot home next to the tiny one.

Shafer, co-owner of the Tumbleweed Tiny House Company, designs and builds miniature homes with a minimalist style that prizes quality over quantity and makes sure no cubic inch goes to waste. Most can be hooked up to public utilities. The houses, which pack a range of amenities in spaces smaller than some people’s closets, are sold for $40,000 to $50,000 ready-made, but cost half as much if you build it yourself.

Tumbleweed’s business has grown significantly since the housing crisis began, Shafer said. He now sells about 50 blueprints, which cost $400 to $1,000 each, a year, up from 10 five years ago. The eight workshops he teaches around the country each year attract 40 participants on average, he said.

“People’s reasons for living small vary a lot, but there seems to be a common thread of sustainability,” Shafer said. “A lot of people don’t want to use many more resources or put out more emissions than they have to.”